1. Field of the Invention
The field of the invention is splice enclosures for optical waveguides.
2. Background of the Invention
Sheet metal pedestals are presently installed in various locations for the connection of copper communication cables. It would promote efficiency to be able to place optical splices in these pedestals. Unfortunately, the pedestals are usually constructed of sheet metal, which does not offer the environmental protection currently required for optical waveguide (optical fiber) splices. The existing copper pedestals in areas such as Wisconsin are also subject to frost heave. Frost heave, associated with the freezing and melting of water in the surface of the ground, can cause the existing pedestals to appreciably rise or fall with respect to the underlying stable ground surface. Copper cables can still be connected to each other in such pedestals by the practice of putting a few extra bends in the copper cables. These bends can accommodate the motion associated with frost heave. However, optical fibers are not malleable. In fact, increased power losses or even cable failure results when optical fibers are bent beyond a certain point, known as their minimum bend radius. Since the optical fiber cables must be buried below the frost layer in current installation practices, most of the fiber optic cable would not move during frost heave. However, the end of the cable would have to come up through the frost layer into the pedestal if the pedestal were to be used for the splicing of optical fiber cables. Therefore, frost heave would subject the optical waveguide fiber cables to tensile, compression, or bending forces when the pedestal itself rises or falls during frost heave. These forces would therefore subject the optical fiber cables to increased power losses or even failure. Such interruptions in service are unacceptable to the telephone companies or other users of optical fiber cable.